As a study on a sensor network becomes active, the necessity of a study on an issue of wirelessly supplying power to each sensor node has been gradually increased. Wireless power transmitter technologies using magnetic resonance field or an electromagnetic induction coupling field are not free in human harmfulness. Therefore, as a solution thereto, an ultrasonic power transmission method is relieved as an alternative.
Researches on an ultrasonic wireless power transmission apparatus have been conducted on a basic study level, and studies on a communication scheme or method using an ultrasonic wireless power apparatus have also been conducted only in a very limited application field.
In researches using the ultrasound for data communication underwater, studies on a underwater channel characteristic and underwater ultrasonic communication have been conducted and based thereon, the high power/high-priced ultrasonic communication modem technologies with various modulation/demodulation techniques and signal processing algorithms have been developed.
A first related art is disclosed in US2011/0218594A1 (Ultrasonic Transducer for Bi-directional Wireless Communication, Eyal Doron) specifying a communication system by using an ultrasonic apparatus transmitting power by using an ultrasonic element. An energy power transmission apparatus using ultrasound, which is provided between an internal apparatus incorporated in a human body and an external apparatus, and a bidirectional communication method using the apparatus were proposed.
A second related art is disclosed in US 2011/0134725A1 (Ultrasonic System and Communication Method Thereof, Chung-Yi Su). A burst transmitter method synchronized with a communication method in an ultrasonic transmitter/receiver system is used.